Clamp



Nov. 1, 1927. 1 ,647,688

M. B. DAVIS CLAMP Filed March 5. 1926 4 Sheets-Sheet 1 INVENTOR ATTO'RNEY Nov. 1, 192 7.

M.-B. DAVIS cum! I Filed March s, 1926 4 Sheets-Sneak fluf 6.

A5, 2a 7 2 7 /l /4- 1 ull ' 'INVENTOR Mar /0504145 ATTOR'NEY Patented Nov. 1, 1927.

UhliTED STATES PATENT OFFICE.

MARVIN B. DAVIS, OF KANSAS CITY, MISSOURI, ASSIGNOR TO GEORGE KRELL, OF SAIP'ULPA, OKLAHOIVIA.

CLAMP.

Application filed March 5,1926. Serial No. 92,459.

My invention relates to clamps for use in oil well operation and commonly termed spiders or elevators in that they are adapted for use in supporting a string of casing, tubing or rod within a well for letting the same into the well or for pulling the same from the well, the device being referred to as a pipe clamp, and its use described in connection with the pulling or letting in of tubing, although such description is not intended as a limitation to employment of the device with tubing only. The principal objectof the present invention is to provide a clamp of the above general description adapted for gripping the tubing proper as distinguished from butt contact with the tubing collar, and for automatically seating the clamp jaws against the tubing by a shift action resulting from contact of the gripping jaws with the tubing collar as the clamp is raised againstthe collar.

In accomplishing this object I have provided improved details of structure, the preferred forms of which are illustrated in the accompanying drawings, wherein:

Fig. 1 is a perspective view of a clamp embodying my improvements, showing the jaws open for application to the tubing.

Fig. 2 is a plan view of the same.

Fig. 3 is a vertical section on the line 3-3, Fig. 2, one of the spring hangers being sectioned for better illustration.

Fig. 4: is an end view of the clamp as it appears when applied to the tubing, but prior to its gripping engagement therewith, parts of the jaws being broken away. i

Fig. 5 is a similar View showing the clamp in gripping engagement with the tubing, part of one of the jaws being broken away to show the gripping contact.

Fig. 6 is a vertical section on the line 66, Fig. 2, particularly illustrating the eccentric hanger connection.

Fig. 7 is an enlarged detail perspective viewof one of the eccentric crank hangers.

Fig. 8 is an enlarged detail perspective view of a jaw coupling.

Fig. 9 is an enlarged detail perspective view of one of the aws and its mounting.

Referring more in detail to the drawings,

1 designates a hanger link whereby the clamp is suspended from a pull cable (not shown) run over a pulley wheel at the top of the derrick in a manner well known in oil well operation.

The clamp suspending mechanism comprises a T block 2 (Fig. 7') for each of the two hinged sections of the clamp, each block comprising a head 3 having a transverse opening 4 within which the base of the link 1 is pivotally mounted, and oppositely directed, paired ears 5 enclosing the upper ends of links 6 which are pivota'lly connected with the cars by pins 7. The lower end of each link 6 is seated in a slot 8 in the apex of a triangular block 9 and pivotallyconnected therewith by a pin 10. Extending laterally from one face of the block is a trunnion 11 pivotally seated in the socket 12 ina coupling bar 13 carrying a cylinder 14 (Fig. '3) having; a head 15 at its lower end through which is projected a shank 16 having a nut 17 on its lower end bearing against the outer face of the cylinder head and having an-eyelet 18 its upper end within the cylinder.

Slidably mounted within the cylinder 14 is a sleeve 19, the upper end of which fits over and is secured to a boss 20 on an extension 21 of the link head 3, the sleeve fitting slidably within the cylinder to form a telescoping joint. Located within the sleeve 19 is a coil spring 22, the lower end of which is hooked into the eyelet 18 and the upper end of which is hooked into the eyelet 23 on the lower end of a shank 24 located Within an aperture 25 in the extension 21 and having its upper end 26 hooked over the top of the extension and anchored in a groove 27 therein. v

The parts just described are duplicated on the opposite pairs of ears 5 on the head 2 so that the .blocks 9 may pivot in balanced 'relation, the trunnions rotating freely within their sockets 12 to support the sleeve 1 1, and being anchored to thecouplings by lag bolts 28 that extend through the closed ,enflls of the sockets 12 into the ends of the trunnions, the lag bolts having bearing portions 29 which turn freely within the closed ends of the sockets.

On the opposite faces of the blocks 9 and arranged eccent-rically to the trunnions 11 are trunnions 30 which are rotatably seated in sockets 31 in jaw frames 32 and are held in place by lag bolts 33 which extend through the frame members into the ends. of the trunnions and have bearing portions 3 1 permitting the trunnions to rotate freely in .the frame members. The combined strength of the four springs 22, which are arranged at all) the four corners of the clamp, is suiiicient to support the weight of the clamp and yieldingly retain it in initial set position which can be shifted against the tension of the springs to set the jaws under the conditions hereinafter described.

The frame members 32 are paired in the respective halves of the clamp and those at the rear provided with hinge ears 36 having openings 37 adapted for registration to receive a hinge pin 38 upon which the clamp members may be opened and closed, the frame members at the front of the clamp being respectively provided with male and female latch portions 39 and 40 adapted for nesting when the clamp is closed. The latch members 39 are provided with apertures e1 adapted to receive the shanks 42 of a U- shaped latch 43 slidable in collars 441: on the outer plates of the latch members 40, and in openings 45 on the inner plates of said memher, the apertures in the collars registering with apertures 41 in the members 39 on the other half of the clamp when the clamp is closed so that the latch shanks may project through all of the apertures and hold the parts together. The latch shanks are yieldingly urged to functional position by springs 46, connected with the shanks 4-2 and with the'collars 44-, so that when the clamp is to be opened, the latch is dawn outwardly against the tension of the springs so to permit the members 39 to be drawn from the members. 40 as the clamp is opened on its hinged joint.

When the clamp is to be closed the latch is also drawn outwardly to permit the members 39 to enter between the plates l0 and then'released to permit the shanks to seat in the complementary latch members. The latch members constitute the front of the clamp the hinged ears the rear of the clamp and the body portions the ends thereof, these parts combining to forma square framework within which the clamping jaws are located.

At the inner corner of each of the frame members 32 is a vertical bore 48, having a flared mouth 4.9 extending to near the bottom of the frame and there provided with a shelf to constitute a bearing and a support for a jaw slip, presently described.

The jaw slips which I prefer to employ in connection with the clamp each constitutes a block 51 having contiguous faces at right angles to each other with a cylindrical rib 52 at its corner adapted for seating in the bearing bore 48 of a jaw raine member 32 and recessed about the ends of the rib to permit the rib to seat within the portion of the bore within the shelf 50 and turn freely within the bore while anchored against lateral displacement therefrom. There is a re cess 53 in each end of the slip to render the slips universal. The slips are anchored at their upper ends by plates 5a which seat on the ends of the frame and slips and are secured thereto by screws or the like 55 which extend through apertures 56 in the plates into threaded sockets 57 in the ends of the frame and of the slips. The plates are also provided with apertures 58 within which the upper ends of the ribs 52 are journalled, the lower ends of the ribs being journalled in portions of the bore 48 located in the shelves 50 at the bottom of the frames. The inner corner faces of the slips are concaved vertically as at 59 and provided with outwardly facing teeth 60 adapted for engagement with the tubing when the clamp is closed to support the tubing by the gripping engagement of the slips therewith.

6i designates Ushaped springs, the lower leaf of each of which is fixed to the top of a slip 51 by a lag bolt or other fastening device 62 which extends through said leaf into a threaded socket ($3 in the top of the slip, the upper leaf of each spring being-concaved at its freeend at to fit about the tubing when the clamp is closed thereover and provide a cushion ng engagement with the tubing collar to se the jaws as will be hereinafter desc 'ibed.

First assuming that the clamp is to be used as an elevator for pulling tubing and that the tubing is suspended in the well with one of its joints projecting above the easing head sufficiently for the clamp to be applied to the tubing below a collar on the upper end of the joint; the clamp is suspended from the pull cable by means of the links 1 and lowered to a point slightly above the casing head. The clamp is opened on its hinge and drawn over the tubing; then closed about the tubing and latched. The clamp is then elevated; the slips moving freely over the tubing until the U springs engage the collar at the upper end of the tubing joint, holding the frame members stationary while the links continue to rise and thereby moving the frame members inwardly on the eccentric crank mounting to force the slips against the tubing; the closing movement of the jaws and slips forcing the teeth on the slips into such gripping relation with the tubing that they will'hold thereagainst and support the weight of the tubing the gripping action being proportional to the weight of the tubing and thereby insuring against sliopage of the clamp along the tubing. l Vhen the top joint of the tubing has been lifted out of the well and the collar of the next joint located a sufficient distance above the casing head to per niit application of another clamp beneath the tubing collar, a second clamp is appliedto the tubing below the collar of the second joint the top joint of tubing is uniii) screwed and carried to a storage position and the clamp removed by opening it onits hinge joint, the springs 21 automatically resetting the jaws to open relation as soon as the clamp is relieved from the weight of the tubing.

The operation just described is then repeated on the next joint of pipe and successively on other joints until all of the .tub ing has been removed from the well.

Use of the clamp for letting in tubing is identical with that of pulling the tubing, in so far as operation of the clamp is concerned, and itis apparent that the clamp may be employed as a spider for suspending the tubing from the casing head.

What I claim and desire to secure by Letters Patent is:

1. In a clamp of the character described, a frame comprising independent jaw members arranged in pairs, a slip on each jaw member, a hanger for each pair of aw men bers, eccentric connection between the hangers and jaw members, and yielding means normally spreading the jaw members to permit free movement of the slips to set positions along an object to be engaged thereby.

2. In a clamp of the character described, a plurality of independent jaw members ar ranged in pairs, each provided with a slip, a hanger for each pair of jaw members eccentric connection between the hanger and the jaw members, and yielding means normally spreading the jaw members to open position and against the tension of which the jaw members are movable to functional position upon engagement of the jaw members with an obstruction on the object to be lifted. e

3. In a. clamp of the character described, a hanger, a block suspended from said hanger, eccentric trunnions on said block, a frame.

member mounted on one of the trunnions, a coupling mounted on the other trunnion, yielding means connecting the coupling with said hanger to normally, yieldingly retain the frame member in initial position, and a slip on the frame member one of the movable parts being-adapted for butting contact with an object to be lifted to shift the frame member and slip to functional position against the tension of said spring, substantially as set forth.

e. In a clamp of the character described,

a hanger comprising a T-head, links on said T-head, blocks suspended from said links having eccentric trunnions on their opposite faces, a coupling on corresponding trunnions of the respective blocks, resilient means connecting the coupling with the hanger, independent frame members on the other corresponding trunnions on said block, and slipscarried by said frame members.

5. In a clamp of the character described,

a pair of frame members, a slip on each of said frame members, a block pivotally connected wit-h each of said frame members, links pivotally connected with said blocks, a hanger pivotally connected with said links, a coupling pivotally connected with said blocks eccentrically of the frame member connections, and resilient means connecting the coupling with the hanger to normally, yieldingly spread the frame members for the purpose set forth.

6. In a clamp ofgthe character described, a pair of frame members, a slip on each of said frame members, a block pivotally connected with each of said frame members, links pivotally connected with said blocks, a hanger pivotally connected with said links, a coupling pivotally connected with said blocks eccentrically of the frame member connections, a collar on said coupling, a sleeve fixed to the hanger and slidable in said collar, and a spring located in said sleeve and connected with said collar and withthe hanger to normally, yieldingly telescope the sleeve in the collar and retain the frame members in spread relation.

7. In a clamp of the character described, a hanger, frame members eccentrically suspended from the hanger and each having a vertical bearing groove, slips having bearing ribs mounted in said grooves to permit hinged movement of the slips on the bearing members, and means normally yieldingly spreading the frame members to permit free movement of the slips over an object to be gripped thereby.

8. In a clamp of the character described, a frame member having a vertical bearing groove provided with a flared mouth, a slip having a corner rib seated in said groove, means foranchoring the rib in the groove to permit the slip to rotate transversely on the frame members, means eccentrically suspending the frame member, and means normally, yieldingly retaining the frame member at one limit of its spreading travel.

9. In a clamp of the character described, a frame member having a longitudinal hearing bore and a flared mouth opening said bore from one end of the frame member to near the opposite end thereof, a slip having a corner rib and annular recesses surrounding the ends of the rib, the rib seating in the bore of the frame and the slip supported on the end of the frame to permit the sli to pivoton the frame member, means anc ioring the slip to the frame member, a hanger eccentric connection between the hanger and the frame member, and yielding means normally spreading the frame member for the purpose set forth.

10. In a clamp of the character described, a frame member, a slip pivotally mounted on the frame member, yielding means on the end of the slip adapted for engagement with a protuberance on the object to be engaged by the slip, a hanger, eccentric connection between the hanger and the frame member, and yielding means normally retaining the frame member at the limit of spread of its eccentric connection.

11. In a clamp of the character described, a frame member, a slip pivotally mounted on the frame member, a t shaped spring on the end of the slip comprising a tree leaf having a concaved recess in its end adapted for engagement with a protuberance on the object to be engaged by the slip. a hanger. eccentric connection between the hanger and the frame member. and yielding means normally retaining the frame member at the limit of spread of its eccentric connection.

12. In a clamp of the character described,

comprising a frame member, a slip having means at one side for pivotally mounting it on the frame member on a longitudinal axis and having a Work engaging face at the opposite side and a leaf spring on the upper end of the slip adapted for engagement With a pipe collar and having a concaved free edge, for the purpose set forth.

13. In a clamp of the character described, a frame member mounted for movement on a horizontal axis, a slip mounted on the frame menber, and a U-shaped spring on the upper end of the slip comprising a free upper leaf engageable With a protuberance on the object to be clamped to rock the frame member on its horizontal axis.

In testimony whereof I aflix my signature.

MARVIN B. DAVIS. 

